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51.
This paper extends the results of Goh [1], and Takeuchi and Adachi [2,3] concerning the generalized linear Volterra model. We introduce a piecewise linear Volterra model for a two- species system. The solution of the steady-state problem is then shown to be equivalent to finding the solution to the Generalized Linear Complementarity Problem. We show when this nonnegative equilibrium is unique and globally asymptotically stable in the sense of Goh [1]. 相似文献
52.
This work shows how disjunctive cuts can be generated for a bilevel linear programming problem (BLP) with continuous variables.
First, a brief summary on disjunctive programming and bilevel programming is presented. Then duality theory is used to reformulate
BLP as a disjunctive program and, from there, disjunctive programming results are applied to derive valid cuts. These cuts
tighten the domain of the linear relaxation of BLP. An example is given to illustrate this idea, and a discussion follows
on how these cuts may be incorporated in an algorithm for solving BLP. 相似文献
53.
Jean-Pierre Aubin Georges Haddad 《Journal of Mathematical Analysis and Applications》2002,275(2):676-692
Given a target contained in a constrained set and an impulse control system governing the evolutions of runs or executions, that are hybrids of continuous and discrete evolutions, this paper studies and provides several characterizations of the capture basin of the target viable in the constrained set. It is the subset of initial runs from which start at least one run viable in the constrained set until it reaches the target in finite time. It also provides algorithms and regulation rules governing the runs that reach the targets while obeying state constraints. 相似文献
54.
A Nitrite Electrochemical Sensor Based on Boron‐Doped Diamond Planar Electrochemical Microcells Modified with a Monolacunary Silicotungstate Polyoxoanion 下载免费PDF全文
Yosra Sahraoui Amel Sbartai Sana Chaliaa Abderrazak Maaref Amor Haddad Nicole Jaffrezic‐Renault 《Electroanalysis》2015,27(6):1359-1367
A new boron doped diamond microcells (BDD) was modified, for rapid, selective and highly sensitive determination of nitrite, using a coating film of polyoxometalates (POMs), formed by cyclic voltammetry on the molecular p‐phenylenediamine (PPD) functionalized BDD. The scanning electron microscopy (SEM) technique was used to examine the morphology of (PPD/SiW11) modified (BDD) electrode. It was found that (SiW11) layer was uniformly formed on the electrode surface. It was observed that (BDD/PPD/SiW11) showed excellent electrocatalytic activities towards nitrite ion. Under the selected conditions, the anodic peak maximum at ?0.6 V was linear versus nitrite concentration in the 40 µM–4 mM range, and the detection limit obtained was 20 µM. The newly developed electrode has been successfully applied to the determination of nitrite content in real river water samples. 相似文献
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N+–HBr–M and (π)C–HBr–M hydrogen bond synthons have been exploited in the crystallization of a series of 2,2′-iminodipyridinium(2+) dication (hereafter 2,2′-imdipyH2), (C10H11N3)[MX4] salts (M = Co and Hg; X = Cl and Br) and 2,2′-iminodipyridinium(1+) cation (hereafter 2,2′-imdipyH), (C10H10N3)2[MX4] salts (M = Co, Hg; X = Cl and Br). Intermolecular interactions and crystal supramolecularity adopted in these structures were analyzed and compared with reported similar structures, (C10H11N3)[CuCl4] and (C10H10N3)2[CoCl4]. In these salts only one structural form for the halometallate species is observed namely mononuclear tetrahedral. The crystal supramolecularity in the (2,2′-imdipyH2)[MX4] series corresponds to three distinct structural motifs: Parallel ribbons of infinitely connected cyclic dimers of two dications and two anions found in the isomorphous salts of [CoCl4]2? and [CuCl4]2?; and cyclic dimer hearing-bone packing motif found in the isomorphous dication salts of [CoBr4]2? and [HgBr4]2?. Infinitely helical layers based on alternating aniontwo stacked cations anion two stacked cations are found in the isomorphous salts of (2,2′-imdipyH)2[CoCl4] and (2,2′-imdipyH)2[HgBr4]. 相似文献
59.
Quinton D Girard A Thi Kim LT Raimbault V Griscom L Razan F Griveau S Bedioui F 《Lab on a chip》2011,11(7):1342-1350
In this work we report on the design, microfabrication and analytical performances of a new electrochemical sensor array (ESA) which allows for the first time the simultaneous amperometric detection of nitric oxide (NO) and peroxynitrite (ONOO(-)), two biologically relevant molecules. The on-chip device includes individually addressable sets of gold ultramicroelectrodes (UMEs) of 50 μm diameter, Ag/AgCl reference electrode and gold counter electrode. The electrodes are separated into two groups; each has one reference electrode, one counter electrode and 110 UMEs specifically tailored to detect a specific analyte. The ESA is incorporated on a custom interface with a cell culture well and spring contact pins that can be easily interconnected to an external multichannel potentiostat. Each UME of the network dedicated to the detection of NO is electrochemically modified by electrodepositing thin layers of poly(eugenol) and poly(phenol). The detection of NO is performed amperometrically at 0.8 V vs. Ag/AgCl in phosphate buffer solution (PBS, pH = 7.4) and other buffers adapted to biological cell culture, using a NO-donor. The network of UMEs dedicated to the detection of ONOO(-) is used without further chemical modification of the surface and the uncoated gold electrodes operate at -0.1 V vs. Ag/AgCl to detect the reduction of ONOOH in PBS. The selectivity issue of both sensors against major biologically relevant interfering analytes is examined. Simultaneous detection of NO and ONOO(-) in PBS is also achieved. 相似文献
60.
Mauko L Pelzing M Dolman S Nordborg A Lacher NA Haddad PR Hilder EF 《Journal of chromatography. A》2011,1218(37):6419-6425
In this study we describe a new method for rapid and sensitive analysis of reduced high mannose and complex glycans using zwitterionic-type hydrophilic interaction nano-liquid chromatography (nano ZIC-HILIC, 75 μm I.D.×150 mm) coupled with high resolution nanoelectrospray ionisation time of flight mass spectrometry (nano ESI-TOF-MS). The retention of neutral glycans increases with increasing molecular weight and is higher for high mannose glycans than for complex-type glycans. The selectivity of ZIC-HILIC for sialylated glycans differs from that for the neutral glycans and is believed to involve electrostatic repulsion; therefore, charged glycans are eluted earlier than neutral glycans with comparable molecular weight. Due to the improved sensitivity achieved by employing a ZIC-HILIC nano-column, a range of less common complex glycans has been studied and the high resolution mass spectrometry enabled confirmation of glycan composition for the proposed structures. Good sensitivity for glycans was achieved without prior fluorescent labelling, and the time of the analysis was significantly reduced compared to the separation of glycans on a conventional-size column. The proposed method offers a fast and sensitive approach for glycan profiling applied to analysis of biopharmaceuticals. 相似文献